Circuit Board Reference Manual

MCF548x Reference Manual, Rev. 3
9-2 Freescale Semiconductor
9.3.1 Module Base Address Register (MBAR)
The supervisor-level MBAR, Figure 9-1, specifies the base address and allowable access types for all
internal peripherals. It is written with a MOVEC instruction using the CPU address 0xC0F (refer to the
ColdFire Family Programmer’s Reference Manual). MBAR can be read or written through the debug
modules as a read/write register, as described in Chapter 8, “Debug Support.” Only the debug module can
read MBAR.
The MBAR is initialized to 0x8000_0000 at reset; however, it can be relocated to a new base address. To
access internal peripherals, write MBAR with the appropriate base address (BA) after system reset.
All internal peripheral registers occupy a single relocatable memory block along 256-KByte boundaries.
MBAR[BA] is compared to the upper 14 bits of the full 32-bit internal address to determine if an internal
peripheral is being accessed. Any accesses in this range, whether to a valid peripheral address or not, will
be made internally rather than using the external bus.
NOTE
The MBAR region must be mapped to non-cacheable space.
Table 9-1. SIU Register Map
Address
(MBAR +)
Name Byte0 Byte1 Byte2 Byte3 Access
CPU+0xC0F Module Base Address Register MBAR R/W
0x04 SDRAM Drive Strength Register
1
1
The SDRAM Drive Strength and Chip Select Configuration registers are discussed in Chapter 18, “SDRAM Controller
(SDRAMC).” They are shown in this memory map for reference purposes.
SDRAMDS
1
R/W
0x08–0x0C Reserved
0x10 System Breakpoint Control Regis-
ter
SBCR R/W
0x1–0x1C Reserved
0x20 SDRAM Chip Select 0
Configuration Register
1
CS0CFG0
1
R/W
0x24 SDRAM Chip Select 1
Configuration Register
1
CS1CFG1
1
R/W
0x28 SDRAM Chip Select 2
Configuration Register
1
CS2CFG2
1
R/W
0x2C SDRAM Chip Select 3
Configuration Register
1
CS3CFG3
1
R/W
0x30–0x34 RESERVED
0x38 Sequential Access Control Register SECSACR R/W
0x3C–0x40 RESERVED
0x44 Reset Status Register RSR R/W
0x48–0x4C RESERVED
0x50 JTAG Device Identification Number JTAGID R